WO2014162767A1

WO2014162767A1 - Rotating machine

Info

Publication number: WO2014162767A1
Application number: PCT/JP2014/052095
Authority: WO
Inventors: 松本　和幸; 貝漕　高明
Original assignee: 三菱重工業株式会社
Priority date: 2013-04-03
Filing date: 2014-01-30
Publication date: 2014-10-09
Also published as: EP2982832A4; KR20150114964A; US10247025B2; EP2982832A1; EP2982832B1; US20160047265A1; JP5951890B2; CN105074134A; JPWO2014162767A1; KR101660204B1; CN105074134B

Abstract

A rotating machine equipped with: a casing (10) in which is formed a cavity (12) in which the tips of rotor blades (50) intrude; multiple sealing fins (17) which extend from the inner circumferential surface of the cavity (12) of the casing (10) toward the tips of the rotor blades (50), thereby sealing the space between the casing (10) and the rotor blades (50); and swirl breakers (2), which have swirl flow collision surfaces (3) in between the multiple sealing fins and extending radially inward from the inner circumferential surface of the cavity (12) of the casing (10), and against which a swirling flow collides, with swirl flow transmission parts (n) that transmit the swirl flow in the circumferential direction being formed in at least a portion of the swirl flow collision surfaces.

Description

Rotating machine

The present invention relates to a rotating machine, and more particularly to a rotating machine provided with a seal mechanism that reduces leakage loss.
This application claims priority on Japanese Patent Application No. 2013-0778029 filed on April 3, 2013, the contents of which are incorporated herein by reference.

In rotating machines such as steam turbines and gas turbines, a sealing mechanism is used to prevent leakage of working fluid such as steam from the gap formed between the stationary side (casing) and the rotating side (blade). It has been. (For example, refer to Patent Document 1).
For example, in order to reduce the passage of the working fluid after passing through the stationary blade through the gap between the blade and the casing (the blade tip cavity), for example, a seal fin extending toward the blade on the inner periphery of the casing A technique for forming a sealing member is known.

JP 2006-104952 A US Patent No. 7,004475

Incidentally, in recent years, there are cases in which self-excited vibrations such as low-frequency vibrations occur in rotating machines. The cause of this self-excited vibration is that a flow (swirl flow) having a strong circumferential velocity component (swirl component, swirl component) that passes through the stationary blades passes through the seal fins and enters the cavity between the seal fins. In other words, an uneven pressure distribution is formed in the circumferential direction.

From such a background, a structure for reducing and attenuating a swirl component is desired for a sealing mechanism of a rotary machine. As such a structure, a technique of installing a baffle plate in a rotor blade tip cavity is known, as in the device described in Patent Document 2.
However, the seal member used in this apparatus has a honeycomb structure including seal fins and baffle plates. Specifically, this honeycomb structure has a structure in which seal fins are divided by a baffle plate extending in the axial direction, and the working fluid cannot enter the structure by the continuous baffle plate. , Swirl reduction effect is low.

An object of the present invention is to provide a rotating machine provided with a seal mechanism that can further enhance the effect of reducing swirling flow.

According to the first aspect of the present invention, a rotary machine includes a rotor having a rotor body that rotates about an axis, and a moving blade that is arranged to extend radially outward from the rotor body. A casing which is disposed so as to surround from the outer peripheral side and has a cavity into which the tip of the moving blade enters, and extends from an inner peripheral surface of the cavity of the casing toward the tip of the moving blade, and the casing and the moving A plurality of seal fins that seal a space between the blades and a swirl that extends inward in the radial direction from the inner peripheral surface of the cavity of the casing and collides with a swirl flow between the plurality of seal fins A swirl breaker having a flow collision surface and a swirl flow passage portion formed in at least a part of the swirl flow collision surface for passing the swirl flow in the circumferential direction. And features.

According to the above configuration, since the swirl breaker is disposed between the seal fins and the swirl flow collides with the swirl breaker, the swirl flow dynamic pressure is attenuated by the swirl breaker and the swirl flow is generated. Can be reduced.
In addition, since the swirl flow passage portion is formed on the swirl flow collision surface, the swirl flow passes through the swirl flow passage portion and flows in the circumferential direction at the radial position where the swirl flow collision surface exists. The reduction effect can be strengthened.

In the rotating machine, the swirl flow passage portion is a gap formed between the swirl flow collision surface and at least one of the seal fin on one axial side and the seal fin on the other axial side. It's okay.

According to the above configuration, the swirl flow passage portion can be formed with a simpler configuration.

In the rotating machine, the swirl flow collision surface may be formed to be inclined with respect to the axial direction so as to be orthogonal to the flow direction of the swirl flow.

According to the above configuration, the swirling flow can be reduced more effectively.

In the rotating machine, the swirl breaker may be formed of a plate-like body, and the swirl flow collision surface may be formed so that the angle with respect to the axial direction is different between the proximal end side and the distal end side. .

According to the above configuration, it is possible to provide a more optimal swirl breaker with respect to the behavior of the swirling flow that repeatedly rebounds between the upstream-side seal fin and the downstream-side seal fin.

In the rotating machine, the swirl breaker may be formed of a plate-like body having at least one hole, and the swirl flow passage portion may be the at least one hole.

According to the above configuration, the swirl breaker can be more optimal for the behavior of the swirling flow by adjusting the diameter, shape, quantity, arrangement, etc. of the holes.

In the rotating machine, dimple processing may be performed on at least one of the swirl flow collision surface of the swirl breaker and the surface of the seal fin.

According to the above configuration, energy loss due to friction between the swirl flow, the swirl breaker, and the seal fin is increased as compared with the case where the swirl collision surface and the seal fin are smooth surfaces. The effect is increased.

In the rotating machine, the swirl breaker may have a configuration in which a cross-sectional shape is a waveform.

According to the above configuration, in addition to the separated flow having the vorticity in the radial direction, a plurality of small-scale vortices having the vorticity in the axial direction and the circumferential direction are generated. Thereby, the disturbance of the flow in the space between the seal fins is amplified, and the effect of reducing the swirling component contained in the steam is increased.

In the rotating machine, the swirl breaker may be configured to have a width that decreases toward the radially inner periphery.
According to the said structure, it becomes easy to guide the leak jet which passed the seal fin in the space enclosed with the seal fin which has installed the swirl breaker, and the effect of a swirl breaker can be strengthened more.

According to the present invention, since the swirl breaker is disposed between the seal fins and the swirl flow collides with the swirl breaker, the swirl flow dynamic pressure is attenuated by the swirl breaker and the swirl flow is reduced. Can be reduced. Further, since the swirl flow passage portion is formed on the swirl collision surface, the swirl flow easily passes through the swirl flow passage portion, and the effect of reducing the swirl flow can be enhanced.

It is sectional drawing which shows schematic structure of the steam turbine which concerns on 1st embodiment of this invention. It is a principal part expanded sectional view of the seal fin of the steam turbine which concerns on 1st embodiment, and is an expanded sectional view of I of FIG. It is the figure which looked at the seal fin of the steam turbine concerning a first embodiment from the diameter direction outside. It is a figure corresponding to FIG. 2 explaining the behavior of the leaking steam flowing into the annular groove when the swirl breaker is not arranged. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. FIG. 5 is a cross-sectional view taken along line BB in FIG. 4. It is a figure explaining the effect | action of the swirl breaker of 1st embodiment. It is a figure corresponding to Drawing 3 explaining the modification of the swirl breaker of a first embodiment. It is a figure corresponding to Drawing 3 explaining the modification of the swirl breaker of a first embodiment. It is a figure corresponding to Drawing 3 explaining the modification of the swirl breaker of a first embodiment. It is a figure corresponding to Drawing 3 explaining the modification of the swirl breaker of a first embodiment. It is a figure corresponding to Drawing 3 explaining the modification of the swirl breaker of a first embodiment. It is a figure corresponding to FIG. 7 of the swirl breaker of 2nd embodiment. It is the figure which looked at the swirl breaker of 2nd embodiment from the radial direction outer side. It is a figure corresponding to FIG. 7 of the swirl breaker of 3rd embodiment. It is a figure corresponding to FIG. 7 of the swirl breaker of the modification of 3rd embodiment. It is a figure corresponding to FIG. 7 of the swirl breaker of the modification of 3rd embodiment. It is a figure corresponding to FIG. 3 of the swirl breaker of 4th embodiment. It is a front view of the swirl breaker of 4th embodiment, Comprising: It is a figure which shows a turning flow collision surface. It is a perspective view of the swirl breaker of 5th embodiment. It is a perspective view of the modification of the swirl breaker of 5th embodiment. It is the figure which looked at the swirl breaker of 5th embodiment from the radial direction outer side. It is a figure corresponding to FIG. 7 of the swirl breaker of 6th embodiment. It is a figure corresponding to FIG. 7 of the modification of the swirl breaker of 6th embodiment. It is a figure corresponding to FIG. 7 of the modification of the swirl breaker of 6th embodiment.

(First embodiment)
Hereinafter, a steam turbine which is a rotating machine according to a first embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the steam turbine 1 of the present embodiment is rotatably provided inside a casing 10, a regulating valve 20 that adjusts the amount and pressure of steam S flowing into the casing 10, and the inside of the casing 10. The rotor 30 for transmitting power to a machine such as a generator (not shown), the stationary blade 40 held by the casing 10, the moving blade 50 provided in the rotor 30, and the rotor 30 are rotatably supported around the axis. The bearing part 60 is provided.

Casing 10 has an internal space hermetically sealed and a flow path for steam S. A ring-shaped partition plate outer ring (stationary annular body) 11 into which the rotor 30 is inserted is firmly fixed to the inner wall surface of the casing 10.

A plurality of regulating valves 20 are attached to the inside of the casing 10. The plurality of regulating valves 20 include a regulating valve chamber 21 into which steam S flows from a boiler (not shown), a valve body 22, and a valve seat 23. When the valve body 22 moves away from the valve seat 23, a steam flow path is formed. The steam S is opened and flows into the internal space of the casing 10 through the steam chamber 24.

The rotor 30 includes a rotor body 31 and a plurality of disks 32 extending from the outer periphery of the rotor body 31 in the radial direction of the rotor 30 (hereinafter simply referred to as the radial direction). The rotor 30 transmits rotational energy to a machine such as a generator (not shown).
The bearing unit 60 includes a journal bearing device 61 and a thrust bearing device 62, and rotatably supports the rotor 30.

The stationary blades 40 extend from the casing 10 toward the inner peripheral side and constitute a group of annular stationary blades arranged radially so as to surround the rotor 30, and are held by the partition plate outer ring 11 described above. . The inner sides of the stationary blades 40 in the radial direction are connected by a ring-shaped partition plate inner ring 14 through which the rotor 30 is inserted.

The annular stator blade group composed of the plurality of stator blades 40 is formed at six intervals in the axial direction of the rotor 30 (hereinafter simply referred to as the axial direction), and converts the pressure energy of the steam S into velocity energy. Then, it flows into the moving blade 50 adjacent to the downstream side.

The rotor blades 50 are firmly attached to the outer peripheral portion of the disk 32 included in the rotor 30, and a large number of the rotor blades 50 are radially arranged on the downstream side of each annular stator blade group to constitute an annular rotor blade group.
These annular stator blade groups and annular rotor blade groups are grouped into one stage. That is, the steam turbine 1 is configured in six stages. Among these, the tip of the moving blade 50 in the final stage is connected to the tips of the moving blades adjacent to each other in the circumferential direction of the rotor 30 (hereinafter simply referred to as “circumferential direction”) and is called a shroud 51.

As shown in FIG. 2, on the downstream side in the axial direction of the partition plate outer ring 11, an annular groove 12 (cavity) whose diameter is increased from the inner peripheral part of the partition plate outer ring 11 and whose inner peripheral surface of the casing 10 is the bottom 13 is formed. Has been. The shroud 51 is accommodated in the annular groove 12, and the bottom portion 13 is opposed to the outer peripheral surface 52 of the shroud 51 in the radial direction via the gap Gd.

The bottom portion 13 is provided with three seal fins 17 (17A to 17C) extending in the radial direction toward the shroud 51. The seal fins 17 (17A to 17C) extend from the bottom 13 toward the inner peripheral side toward the outer peripheral surface 52 of the shroud 51, and extend in the circumferential direction. These seal fins 17 (17A to 17C) form a minute gap m with the outer peripheral surface 52 of the shroud 51 in the radial direction.

The dimensions of these minute gaps m may be such that the seal fins 17 (17A to 17C) and the moving blade 50 come into contact with each other in consideration of the thermal elongation amount of the casing 10 and the moving blade 50, the centrifugal extension amount of the moving blade 50 and the like. There is no setting.

A plurality of swirl breakers 2 are arranged at predetermined intervals in the circumferential direction between seal fins 17 adjacent in the axial direction. The swirl breakers 2 are arranged at equal intervals in the circumferential direction. Specifically, the swirl breaker 2 extends between the seal fins 17A and the seal fins 17B so as to protrude radially inward from the inner peripheral surface (bottom portion 13) of the annular groove 12 of the casing 10. It is a plate-like body.

As shown in FIG. 3, one surface of the swirl breaker 2 is a swirl flow collision surface 3 on which a swirl flow collides. The swirl flow collision surface 3 is arranged along the axial direction and faces one side in the circumferential direction (indicated by reference numeral C).

Further, the swirl breaker 2, the seal fin disposed on the first side (upstream side) in the axial direction of the swirl breaker 2 and the second side (downstream side) in the axial direction opposite to the first side. A gap n functioning as a swirl flow passage portion is formed between 17. That is, the swirl breaker 2 and the seal fin 17 are not connected in the axial direction. The dimension of the gap n will be described later.

Here, operation | movement of the steam turbine 1 which consists of said structure is demonstrated.
First, when the regulating valve 20 (see FIG. 1) is opened, the steam S flows into the internal space of the casing 10 from a boiler (not shown).

The steam S flowing into the internal space of the casing 10 sequentially passes through the annular stator blade group and the annular rotor blade group in each stage.
The steam S increases in the circumferential velocity component while passing through the stationary blade 40 in the annular stationary blade group of each stage. Most of the steam SM out of the steam S flows between the rotor blades 50, and the energy of the steam SM is converted into rotational energy, so that the rotor 30 is rotated.

On the other hand, a part of the steam S (for example, about several percent) of the steam SL flows out from the stationary blade 40 and then flows into the annular groove 12 in a state where the circumferential component is increased, that is, in a swirl flow.
Here, the behavior of the leaked steam SL flowing into the annular groove 12 when the swirl breaker 2 is not disposed will be described.

As shown in FIG. 4, a part of the leaking steam SL leaks having an axial velocity calculated as a function of the magnitude of the differential pressure between the upstream side and the downstream side of the seal fin 17A when it exceeds the seal fin 17A. The jet LJ flows toward the axially adjacent seal fins 17B.
On the other hand, as shown in FIG. 5, the leaking steam SL flows as a swirling flow having a circumferential component Vc into the fin space F surrounded by the front and

rear seal fins

17A and 17B. That is, the swirling flow has a strong circumferential component Vc at the exit of the stationary blade 40, and the velocity of the circumferential component Vc is higher than the velocity component Vx in the axial direction.

The swirling flow is swirled in the circumferential direction along the circumferential direction by the viscosity of the leak jet LJ passing through the seal fins 17 (see FIGS. 4 and 5). Further, the flow in the vicinity of the leak jet LJ has a flow pattern as shown in FIG.

Next, the behavior of the leaked steam SL when the swirl breaker 2 is installed will be described.
As shown in FIG. 7, the swirl flow that is the leaked steam SL flows in a spiral between two seal fins 17 adjacent in the axial direction while passing over the seal fins 17A on the upstream side in the axial direction (reference S1). When the seal fins 17B on the downstream side in the axial direction are hit, they are returned (indicated by reference numeral S2). The revolving swirl flow S2 collides with the swirl flow collision surface 3 of the swirl breaker 2 after rebounding by hitting the seal fin 17A on the upstream side in the axial direction. Thereby, the swirl flow S2 is reduced.

On the other hand, the swirl flow S2 passes through the gap n between the swirl breaker 2 and the seal fin 17. That is, the swirl flow S2 flows out to the other side in the circumferential direction without being completely blocked by the swirl breaker 2. Here, the clearance n between the swirl breaker 2 and the seal fin 17 is allowed to pass through the clearance n and the area of the swirl breaker 2 necessary for reducing the swirl flow S2 by colliding with the swirl flow S2. The amount is appropriately adjusted according to the amount of the desired swirl flow S2.

According to the above embodiment, the swirl flow collides with the swirl breaker 2 by arranging the swirl breaker 2 between the seal fin 17 and the seal fin 17. Thereby, the dynamic pressure of the swirl flow can be attenuated by the swirl breaker 2, and the swirl component contained in the steam SL can be reduced.

Further, since the gap n is formed between the swirl breaker 2 and the seal fin 17, the swirl flow easily passes through the gap n, and the effect of reducing the swirl flow is strengthened.

Moreover, since the swirl flow collision surface 3 of the swirl breaker 2 is installed so as to be orthogonal to the flow direction of the swirl flow, the swirl flow can be reduced more effectively.
In addition, since the clearance n between the swirl breaker 2 and the seal fin 17 is the swirl flow passage portion, the swirl flow passage portion can be formed with a simpler configuration.

Note that the swirl breaker 2 may be different in angle and position with respect to the axial direction of the swirl breaker 2 from the above-described embodiment as long as the swirl flow flowing from one circumferential direction can escape to the other circumferential direction. . That is, the configuration of the swirl breaker 2 and the gap n can be appropriately adjusted according to the behavior of the swirling flow.
For example, as shown in FIG. 8, the swirl flow collision surface 3 of the swirl breaker 2 may be arranged so as to be inclined with respect to the axial direction (indicated by the symbol X). The angle of the swirling flow collision surface 3 with respect to the axial direction is appropriately adjusted according to the behavior of the swirling flow S2. Specifically, the swirl flow collision surface 3 is adjusted to be orthogonal to the flow direction of the swirl flow S2.

Note that the individual swirl breakers 2 need not be formed continuously. For example, as shown in FIG. 9, a slit 54 along the radial direction may be provided in the center of the extending direction along the axial direction of the swirl breaker 2.
Further, as shown in FIG. 10, the swirl breaker 2a on the first axial side and the swirl breaker 2b on the second axial side may be alternately arranged in the circumferential direction.

In addition, the clearance n is provided between the swirl breaker 2 and the downstream seal fin (seal fin 17B in FIG. 7) after the swirl flow S2 passes in the circumferential direction and reaches the vicinity of the casing 10, and then the swirl direction. Since it can collide with the downstream swirl breaker 2, it is preferable.

For example, as shown in FIG. 11, only one side in the axial direction of the swirl breaker 2 may be connected to the seal fin 17. That is, the gap n may be formed only on the second side of the swirl breaker 2 in the axial direction.
Furthermore, as shown in FIG. 12, the swirl breaker 2 whose one side in the axial direction is connected to the seal fin 17 and the swirl breaker 2 whose second side in the axial direction is connected to the seal fin 17 are alternately arranged in the circumferential direction. It is good also as a structure which arrange | positions.

(Second embodiment)
Hereinafter, the rotary machine of 2nd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIGS. 13 and 14, the swirl breaker 2 B of the rotating machine according to the present embodiment has the inclination of the swirl flow collision surface 3 such that the base end side (radially outer circumferential side) and the distal end side (radial direction) of the swirl breaker 2 B. The inner circumference side).

Specifically, the swirl breaker 2B includes a proximal end portion 5 and a distal end portion 6, and the proximal end portion 5 and the distal end portion 6 are connected so as to be twisted. The base end portion 5 is inclined with respect to the axial direction so that the principal surface thereof is orthogonal to the flow direction of the swirling flow S2 rebounded by the downstream seal fin 17B. The angle of the tip portion 6 is adjusted so as to cancel the swirling component of the swirling flow S2 rebounded by hitting the upstream seal fin 17A.

According to the above embodiment, a more optimal swirl breaker can be provided for the behavior of the swirl flow S2 that repeatedly rebounds between the upstream-side seal fin 17A and the downstream-side seal fin 17B.

(Third embodiment)
Hereinafter, the rotary machine of 3rd embodiment of this invention is demonstrated based on drawing. In the present embodiment, differences from the first embodiment described above will be mainly described, and description of similar parts will be omitted.
As shown in FIG. 15, the swirl breaker 2 C of the present embodiment is formed of a porous plate-like body in which a plurality of holes 9 are formed, and both axial ends thereof are connected to the seal fins 17. That is, the plurality of holes 9 function as a swirl flow passage portion.

According to the above embodiment, the rigidity of the seal device can be increased by connecting the swirl breaker 2C and the seal fin 17 to each other.
The diameter, shape, quantity, arrangement, etc. of the holes 9 can be changed as appropriate. For example, as shown in FIG. 16, a single hole 9A may be arranged at the approximate center of the swirl breaker 2C. Moreover, as shown in FIG. 17, you may arrange | position the single rectangular hole 9B in the approximate center of the swirl breaker 2C. In this way, by changing the configuration of the holes, it is possible to obtain a more optimal swirl breaker with respect to the behavior of the swirling flow.

(Fourth embodiment)
Hereinafter, the rotary machine of 4th embodiment of this invention is demonstrated based on drawing.
As shown in FIGS. 18 and 19, the swirl flow collision surface 3 of the swirl breaker 2 D of the present embodiment and the surface of the seal fin 17 are subjected to dimple processing (unevenness processing like the surface of a golf ball). ing. That is, a plurality of concave portions 55 regularly arranged are formed on the swirl flow collision surface 3 and the surfaces of the seal fins 17.
The concave portion 55 may be a hemispherical concave portion or a conical concave portion. Alternatively, a concave portion having a pyramid shape such as a hexagonal pyramid shape may be used. Further, the dimple processing need not be formed on both the turning collision surface 3 and the surface of the seal fin 17, and may be formed on either the turning collision surface 3 or the seal fin 17.

According to the embodiment, energy loss due to friction between the swirl flow and the swirl breaker 2D and the seal fin 17 is increased as compared with the case where the swivel collision surface 3 and the seal fin 17 are smooth surfaces. The effect of reducing the included swirl component is increased.

(Fifth embodiment)
Hereinafter, the rotary machine of 5th embodiment of this invention is demonstrated based on drawing.
As shown in FIG. 20, the swirl breaker 2 E of the present embodiment has a corrugated cross-sectional shape as viewed from the direction along the connection side 56 with the bottom surface 13 (see FIG. 2). In other words, the swirl breaker 2E of the present embodiment has one direction orthogonal to the main surface from the base end side (radial outer peripheral side indicated by reference sign R) to the distal end side (radial R inner peripheral side) and vice versa. It is formed into a waveform that curves continuously in the direction. The waveform may be a rectangular waveform or a sine waveform.

Further, by making the swirl breaker 2E corrugated, the depth of the groove 57 (concave shape) parallel to the connection side 56 formed on the turning collision surface 3 is increased toward the downstream (arrow S2E). Is preferred.

According to the above embodiment, in addition to the separated flows MV1 and MV2 having the vorticity in the radial direction R formed by the swirl breaker 2 of the first to fourth embodiments, the axial direction X and the circumferential direction C A plurality of small vortices SV having vorticity are generated. Thereby, the disturbance of the flow in the space between the seal fins 17 (see FIG. 2) is amplified, and the effect of reducing the swirling component contained in the steam SL is increased.

In addition, as shown in FIG. 21, the swirl breaker 2E has a shape viewed from the base end side (radial direction R outer peripheral side) to the distal end side (radial direction R inner peripheral side) toward the swirl flow S2. It is good also as the circular arc shape which becomes convex or concave. That is, the swirl flow collision surface 3 may be curved.

Further, as shown in FIG. 22, the swirl breaker 2E has an arc shape in which the proximal end portion 5 (radially outer peripheral side, connection side 56) is concave toward the swirl flow S2, and the distal end portion 6 (radial direction). It is good also as circular arc shape which becomes convex toward the swirl | vortex flow S2. The proximal end portion 5 and the distal end portion 6 are smoothly connected and are three-dimensionally twisted.

(Sixth embodiment)
Hereinafter, the rotary machine of 6th embodiment of this invention is demonstrated based on drawing.
As shown in FIG. 23, the swirl breaker 2F of the present embodiment has a shape with a narrower width from the proximal end portion 5 (radially outer peripheral side) toward the distal end portion 6 (radial inner peripheral side). . Specifically, the swirl flow collision surface 3 of the swirl breaker 2F has a trapezoidal shape in which the longer bottom of the pair of bottoms is connected to the casing and the shorter bottom is disposed on the shroud 51 side.

According to the embodiment, the leak jet LJ that has passed through the seal fin 17 can be easily guided into the space surrounded by the seal fin 17 where the swirl breaker 2F is installed, and the effect of the swirl breaker 2F is further enhanced. Can do.

In addition, the swirl breaker 2F of this embodiment is not restricted to a shape as shown in FIG. For example, as shown in the modification of FIG. 24, the half on the side of the base end 5 is made the same width as the swirl breaker 2 of the first embodiment, and the half on the side of the tip 6 is made wider than the half on the base end. It is good also as a stepped shape which makes it narrow.
Further, as shown in the modification of FIG. 25, the side 58 on the upstream seal fin 17 side may have a trapezoidal shape along the seal fin 17.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. Moreover, the structure which combined the characteristic demonstrated by said several embodiment arbitrarily may be sufficient.
For example, the swirl breaker is not limited to a planar shape, and may be a curved plate shape.
Moreover, although the outer peripheral surface 52 of the shroud 51 of each said embodiment is a planar shape, the swirl breaker of this invention is applicable also to the shroud in which the step was formed in the outer peripheral surface 52. FIG.

DESCRIPTION OF SYMBOLS 1 Steam turbine 2 Swirl breaker 3 Swirling flow collision surface 5 Base end part 6

Tip part

9, 9A, 9B Hole (swirl flow passage part)
10 Casing 11 Partition outer ring 12 Annular groove (cavity)
13 bottom 14 partition

inner ring

17, 17A, 17B, 17C seal fin 20 regulating valve 21 regulating valve chamber 22 valve body 23 valve seat 30 rotor 31 rotor body 32 disk 40 stationary blade 50 moving blade 51 shroud 52 outer peripheral surface 54 slit 55 recess 60 Bearing portion 61 Journal bearing device 62 Thrust bearing device m Minute clearance n Clearance (swirling flow passage)
F Fin space Gd Gap LJ Leak jet S1, S2 Swirl S, SL, SM Steam

Claims

A rotor having a rotor body that rotates around an axis, and a rotor blade that is arranged to extend radially outward from the rotor body;
A casing which is disposed so as to surround the rotor from the outer peripheral side and in which a cavity into which a tip of the moving blade enters is formed;
A plurality of seal fins extending from an inner peripheral surface of the cavity of the casing toward a tip of the moving blade, and sealing a space between the casing and the moving blade;
Between the plurality of seal fins, the casing has a swirling flow collision surface extending radially inward from an inner peripheral surface of the cavity of the casing and colliding with a swirling flow, and at least one of the swirling flow collision surfaces. A swirl breaker in which a swirl flow passage portion is formed to pass the swirl flow in the circumferential direction.
The swirl flow passage portion is a gap formed between the swirl flow collision surface and at least one of the seal fin on one side in the axial direction and the seal fin on the other side in the axial direction. The rotating machine according to claim 1.
3. The rotating machine according to claim 1, wherein the swirl flow collision surface is formed to be inclined with respect to the axial direction so as to be orthogonal to the flow direction of the swirl flow.
The swirl breaker is formed of a plate-like body,
3. The rotating machine according to claim 1, wherein the swirl flow collision surface is formed such that an angle with respect to the axial direction is different between a proximal end side and a distal end side thereof.
The rotating machine according to claim 1, wherein the swirl breaker is formed of a plate-like body having at least one hole, and the swirl flow passage portion is the at least one hole.
6. The rotating machine according to claim 1, wherein at least one of the swirl flow collision surface of the swirl breaker and the surface of the seal fin is dimpled.
The rotary machine according to any one of claims 1 to 6, wherein the swirl breaker has a corrugated cross-sectional shape.
The rotating machine according to any one of claims 1 to 7, wherein the swirl breaker is formed so that a width thereof becomes narrower toward a radially inner peripheral side.